Renegade (Books of History Chronicles: Lost #3)

As Johnis, Silvie, Billos, and Darsal continue their quest for the four still missing Books of History, Billos makes a decision that has devastating consequences for himself and his companions, especially the devoted Darsal.

Long Synopsis:

One of the chosen has gone "Renegade". Turning his back on all that he once believed, Billos enters the forbidden book and lands in a reality that is as foreign to him as water is to oil. A place called Paradise, Colorado, where he discovers he has strange new powers given to him courtesy of a mysterious figure known as Marsuvees Black. The chosen four have survived the desert, escaped the Black Forest, battled the Horde, and added a spirited refugee to their number. But nothing has prepared them for the showdown that Billos, the renegade, will lure them into.